Oil mist lubrication and oil immersion system

ABSTRACT

An improved oil mist lubrication and oil immersion system for use in the lubrication and protection of machine elements. A sealed housing containing a rotating shaft journalled therein which bears machine elements, the latter being partially immersed in a reservoir of oil contained in the bottom of the housing and provided as a secondary source of lubrication. A lubricant oil is dispersed in air to form an oil mist, or oil aerosol, which is manifolded and then supplied under pressure via a conduit to the sealed housing. A closed loop, preferably provided with a transparent sight tube, is communicated with and located in parallel with the sealed housing, the lower portion of the loop being filled with oil from the reservoir, the level of the reservoir preferably being visually displayed by the sight tube. Aerosol at above atmospheric pressure is supplied to the housing, generally above the oil level, and to the upper portion of the closed loop, the pressure between the housing and closed loop being thus equalized, thus preventing fluctuations in the liquid level, and oil spillage. Communicated with and in sealed relationship with the closed loop, a reservoir is also provided with oil collection means for collection of accumulated oil, the sealed reservoir also being maintained at the same pressure that is applied upon the reservoir of oil within the housing, and upon the oil in the closed loop.

United States Patent 11 1 Thomas Mar. 18, 1975 1 OIL MIST LUBRICATION AND OIL IMMERSION SYSTEM [76] Inventor: Henry A. Thomas, 423 Castle Kirk Ave., Baton Rouge, La. 70808 221 Filed: Aug. 2, 1973 21 Appl. No.: 384,971

Primary Examiner-Manuel A. Antonakas Attorney, Agent, or Firm- Llewellyn A. Proctor [57] ABSTRACT An improved oil mist lubrication and oil immersion system for use in the lubrication and protection of machine elements. A sealed housing containing a rotating shaft journalled therein which bears machine elements, the latter being partially immersed in a reservoir of oil contained in the bottom of the housing and provided as a secondary source of lubrication. A lubricant oil is dispersed in air to form an oil mist, or oil aerosol, which is man ifolded and then supplied under pressure via a conduit to the sealed housing. A closed loop, preferably provided with a transparent sight tube is communicated with and located in parallel with the sealed housing, the lower portion of the loop being filled with oil from the reservoir, the level of the reservoir preferably being visually displayed by the sight tube. Aerosol at above atmospheric pressure is supplied to the housing, generally above the oil level, and to the upper portion of the closed loop, the pres sure between the housing and closed loop being thus equalized, thus preventing fluctuations in the liquid level, and oil spillage. Communicated with and in sealed relationship with the closed loop, a reservoir is also provided with oil collection means for collection of accumulated oil, the sealed reservoir also being maintained atthe same pressure that is applied upon the reservoir of oil within the housing, and upon the oil in the closed loop.

10 Claims, 2 Drawing Figures m n mum I 8|!JT5 sum 1 2 FIGURE 1.

FIGURE Z OIL MIST LUBRICATION AND OIL IMMERSION SYSTEM Oil mist lubrication systems for the lubrication of machine elements, e.g., gears, bearings, and other moving parts of machine tools, compressors, pumps, turbines, and the like, are now well established in industry. In such systems, an oil lubricant is dispersed in air as finely divided particles which form an aerosol, and the aerosol is conveyed via a low pressure distribution system to numerous individual locations for lubrication applications. The oil particles of the aerosol are coalesced at the sources of application upon impact with the surface to be lubricated, this occurring when the aerosol is contacted and the oil particles are impacted at suitable velocity.

A typical oil mist lubrication system includes generally a supply of oil, a supply of compressed air, and a suitable oil mist generator for forming the aerosol. The oil aerosol is conveyed via appropriate piping to a manifold from which individual taps or lines are employed to take off portions of the aerosol. Reclassifiers associated with the individual lines are located at the points of application for coalescence of the oil in the desired form for the applications. Such systems also generally include pressure regulators and control devices. Reference is made to Mist Oil Lubrication, a publication by the Marketing Services Division, Lubricant Department, Chevron Research Company of Richmond, California (Copyright 1970), which presents an excellent description of oil mist systems, their requirements, their theory and their use. This reference is herewith incorporated as a part of the present disclosure.

Oil mist lubrication systems offer certain profound advantages over older methods of lubrication, e.g., the elimination of contaminants, and have become widely established, particularly in moderate to large manufacturing establishments which often include multiple production units, individual units of which often contain literally scores of pumps, compressors and turbines which must be operated continuously, month-aftermonth and year-after-year. In fact, some of the machinery, e.g., turbines, require oil mist lubrication as opposed to the older methods of lubrication. In any regard, despite the advantages offered by oil mist lubrication, the shaft portions of such machinery, supported on one or more bearing members, or gears associated therewith, is most often mounted within a closed bearing or gear box housing above a pool of oil contained therein such that on rotation of the shaft the lower portion of the bearings or gears, or a slinger ring, continuously picks up oil from the oil pool, within which they are partially immersed, so that the bearin gs or gears are constantly wetted by a film of oil. Lubrication is also applied by an oil mist system, concurrently employed, the idea being that the oil mist lubrication system shall serve as the primary and preferred source of lubrication but, in the event of its failure, sufficient oil shall nonetheless be applied by the pool of oil within the bearing or gear box housing to prevent costly breakdowns and loss of production.

A combination oil mist lubrication and oil immersion system of the type characterized is thus described by reference to US. Pat. No. 3,502,186 by Frederick M. Hewitt, which patent was issued on Mar. 24, 1970. In particular, the Hewitt patent discloses an apparatus combination which comprises a closed bearing housing on which is mounted a vertically adjustable oil level sight assembly and oil mist supply tube. The vertically adjustable oil level sight assembly is characterized generally as a U-shaped tube, one terminal end of which is connected upon a wall of, enters into and is in open communication with the lower portion of the closed bearing housing below the oil level, and the loop portion thereof is extended downwardly below the closed bearing housing. The opposite terminal end of the U- shaped tube is extended upwardly and on the end thereof is mounted a transparent tubular shaped sight tube, with a side downwardly inclined vent hole which is open to the atmosphere. The top of the transparent tubular shaped tube is also provided with a removable plug, and it is also open to the atmosphere. Pursuant to this combination, the U-shaped tube is filled with oil from the oil pool within the closed bearing housing, the oil filling both legs of the U-shaped tube, and the transparent sight tube, this permitting visual observation of the level of the oil in the housing, and adjustment of the oil level by the bleed hole located within the transparent sight tube. The end of the U-shaped tube at the location of entry into the lower wall of closed bearing housing is also fitted with a concentrically aligned delivery tube which enters into the closed bearing housing below the surface of the pool of oil, through which oil mist is continuously passed. Whereas the overall apparatus combination described by the l-lewitt patent is generally effective in accomplishing its overall objective by providing not only a primary but also a secondary source of lubrication for the protection of bearings, gears and the like, and has achieved commercial significance, it nonetheless suffers certain serious deficiencies and shortcomings. For one thing, the oil pool within the closed housing and U-tube is subjected to fluctuating pressures, and as a result incorrect liquid levels are often indicated by readings taken from the transparent sight tube. For example, if the pressure within the closed bearing housing is lower than atmospheric, a lower level is indicated in the closed bearing housing than the actual oil level. Over immersion of machine parts within the oil pool, with its attendant disadvantages, can result. Conversely, if the pressure within the closed bearing housing is higher than atmospheric, a higher level is indicated within the closed bearing housing than the actual oil level. Higher than atmospheric pressure within the closed bearing housing causes oil to be discharged through the side downwardly inclined vent hole within the transparent sight tube. In any event, accumulating oil must be bled off through the vent hole, this posing a problem in that recovery of the oil from drains and streams is essential to avoid pollution problems. Not only is this quite messy, but it also increases the cost of operation and maintenance. An even more serious problem, however, is created when the oil level of the pool within the closed bearing housing falls sufficiently that it can no longer serve as a secondary source of lubrication, and hence bearings, gears and the like are left unprotected in the event of a failure of the oil mist lubrication system.

Oil mist lubrication systems of the prior art provide maximum protection when the oil mist or aerosol is conducted through conduits and machine elements at pressures moderately above atmospheric to prevent entry of contaminants into the system. Present oil mist lubrication systems require the passage of some of the oil mist or aerosols through machine elements, prior to venting the aerosol to ambient pressure. They also require venting of some of the oil aerosol to the atmosphere to prevent false readings and in so doing causes more of the aerosol to escape as a stray mist or fog to the atmosphere. To quote from Page of the Chevron publication, supra, .stray mist or fog can be one of the most troublesome problems associated with oil mist systems, particularly with high mist systems inside buildings. Even with well designed equipment, it is not possible to eliminate stray mist completely. With satisfactory operation, a large amount of stray mist can be produced, although the machine element is effectively lubricated. Because the machine element and nozzle cannot be completely sealed, this mist escapes and is lost. The surrounding work area can also be polluted with oil aerosols that may be hazardous to health."

Solutions to these problems are desiderata within the present state of the art, and it is to this end that the present invention is addressed.

it is, accordingly, a primary objective of the present invention to meet these needs, in whole or in part.

A particular object is to provide a new and improved oil mist lubrication and oil immersion system which will provide more reliable observations of actual oil levels within closed bearing housings, and eliminate fluctuating oil levels, regardless of changing pressures.

Another particular object is to provide an oil mist lubrication system wherein escape of the oil mist or aerosol as stray mist into the atmosphere can be suppressed, even when the system is subjected to considerably high pressures, while yet accurate and reliable readings of the oil level can be made.

A more specific object is to provide apparatus which will eliminate or suppress messy oil overflow, contamination and pollution, both as relates to oil spillage and even atmospheric contamination.

These objects, and others, are achieved in accordance with the present invention which relates to improvements in oil mist lubrication systems, particularly combination oil mist lubrication and oil immersion systems, wherein is included the usual oil supply source, compressed air source, suitable oil mist generator for forming the oil aerosol, piping and manifold, and aerosol supply lines leading from the manifold to the closed housings for the various machine elements which are to be contacted and lubricated by the aerosol in association with means hereinafter specifically described. These means include the combination of a closed housing within the confines of an enclosing wall of which is mounted a shaft, and the machine elements associated therewith which are to be lubricated, a first conduit, or aerosol supply conduit entering into the wall of and in open communication with a portion of the closed housing, and a second, or closed conduit, preferably provided with an intermediate transparent section, one terminal end of which is connected through the lower wall of and in open communication with the interior of said closed housing and the other terminal end of which is connected through an upper wall of said closed housing and in open communication therewith. A reservoir, or oil collection means, in association with the second, or closed conduit, is provided to collect the oil which accumulates within the housing after coalescence and drainage from the lubricated machine elements. An oil level is maintained within the bottom portion of the closed housing, above the location of entry of the lower connecting terminal end of the second, or closed conduit, and the intermediate transparent section is maintained at such height that an oil level is reached and maintained therein by oil which enters therein from the closed housing. Aerosol which enters into the upper portion of the closed housing via the first, or aerosol supply conduit enters into a vapor space above the oil level, the pressure being transmitted via the upper connecting end of the second, or closed, conduit to equalize or maintain the same pressure on both the oil level within the closed housing and the oil level within the transparent section of the second, or closed conduit. The same pressure which is applied upon the oil within the housing and closed conduit is also applied within the oil collection means or reservoir. In a preferred embodiment, the oil collection means comprises an overflow line leading from the intermediate transparent section to a container, or reservoir, at equilibrium pressure with that maintained within the vapor space of the closed housing and transparent section of the closed conduit.

These and other features and advantages will be better understood by reference to the following detailed description of a specific embodiment and to the accompanying drawings, to which reference is made in the description.

In the drawings:

FIG. 1 depicts in part, in schematic fashion, a typical oil mist lubrication system and, in part, a combination oil mist lubrication and oil immersion type system in accordance with the present invention as provided in combination with a centrifugal pump bearing assembly, and

FIG. 2 depicts a sectional view of an especially preferred type of oil mist lubrication and oil immersion system pursuant to this invention.

Referring to FIG. 1 there is shown generally a schematic representation of an oil mist lubrication system, a system which distributes under very low pressure, finely divided oil particles in air to the locations to be lubricated. The box depicted by numeral 1 thus represents an air supply source, and a heater 2 is located nearby for warming the air. Numeral 3 depicts the location of an oil supply, the air and oil being brought together within an oil mist generator 4 for formation of an oil aerosol or oil mist. An auxiliary oil supply, and heater 5, is generally positioned adjacent thereto and a detection station 6 with its attendant control devices (not illustrated) is generally used to maintain a constant pressure within the manifold 7, which provides a plurality of taps or lines 8, 8,, 8 .8, from which aerosol can be withdrawn for lubrication of a multiple number of machines which require lubrication.

In general, the apparatus of the present invention is constituted of an improved type of oil feed lubrication and level control device 10 in combination with a closed housing 40, within the confines of the enclosing wall 41 of which the rotatable shaft 42 of a machine 43, e.g., a compressor which requires lubrication, is mounted. The rotatable shaft 42 is supported upon one or a plurality of bearings 44 located within housing 40. The lower portions of bearings 44 are immersed within a pool of oil 45 which serves as a secondary source of lubrication. Oil mist, which serves as the primary source of lubrication for the bearings 44, is injected into the housing 40 via oil aerosol supply conduit 8 which extends from manifold '7, and enters into the confines of the housing 40 via an opening in wall 4].

This figure also illustrates a preferred type of construction for connecting the aerosol supply line 8 with the housing 40, for use in the introduction of oil mist or aerosol. The line 8 is thus passed through a T pipe connection 11, through an opening in the apex of the wall 41 of housing 40, and extends into the vapor space above the surface of the oil pool 45. The line 8, at the upper side of the axially open portion of T pipe connection 11, is snugly projected through fittings 9,12 which not only provides support but also closes off and seals the upper side of the T pipe connection 11. The T pipe connection 11, and the nipple 13 by virtue of which the T pipe connection 11 is secured within the wall 41 of housing 40 form, in effect, an outershell or wall within which the smaller diameter line 8 is concentrically mounted. The annulus between the external wall of line 8 and the inside wall of members 11,13 provides an annular passageway, connecting the interior of housing 40 via the branched side of T connection 11 with the upper portion of line 14, fitted to the T connection 11 via fittings 28,29. The lower portion of line 14, it will be observed, is connected through a transparent sight tube 15 and appropriate fittings 16,17 to the bottom of housing 40 below the surface level of the oil pool 45 and is in open communication therewith permitting ingress and egress of oil between oil pool 45 and line 14. Thus, the upper portion of line 14 is in open communication with the vapor space above the oil pool 45, and the lower portion of line 14 is in open communication with the oil pool 45, this in effect forming a loop or circuit between the inside of housing 40 and the oil feed lubrication air level feed control device 10.

With reference to the lower portion of the loop, it will be noted that one terminal end of the lower section of line 14 is fitted via threaded connection into the wall 41 of housing 40 and an opposite end of this specific segment of conduit is fitted into the branched side of a T connection 18, and the latter is, in turn, affixed via threaded connection at its upper axial open end through a nipple 19 to the transparent sight tube 15. The lower open end of the T connection 18 is sealed via fittings 21,31, these fittings also supporting a tubular member or conduit 22, the upper end of which extends upwardly into the transparent sight tube 15. It will be observed that the tubular member 22 is of a smaller outside diameter than the inside diameter of the T connection 18, and nipple 19, within which the said member 22 is concentrically located, this leaving an annular passageway through which oil can flow within loop 14. Additionally, it will be observed that the upper terminal end of tubular member 22 provides an overflow feature for adjustment and control of the oil liquid level of oil pool 45, oil overflowing into tube 22 being collected within the transparent container 23 affixed via suitable connections 24,25 upon the lower terminal end of tubular member 22. The lower end of container 23, it will be noted, is sealed so that the pressure therein is the same as in transparent sight tube 15. The fittings 26,27 located at the bottom of container 23, however, do provide a means by virtue of which overflow oil can be conveniently withdrawn and collected at suitable times.

In operation, the aerosol or oil mist is transmitted at above atmospheric pressure via lines 8,14 into the vapor space above the oil pool 45 and transparent sight tube 15, respectively. Since there is no difference in the pressure transmitted, and since the pressure above the liquid oil is balanced at all times, even during pressure fluctuations, the oil liquid level within the housing 40 is identical in height with the level within the transparent sight tube 15. The level of the oil pool 45 is readily observed by reference to transparent sight tube 15. There is no overflow of oil from transparent sight tube 15 as a result of a higher unbalanced pressure within the housing 40, and the level of oil in housing 40 is identical in height with the level within the transparent sight tube 15. The level of the oil pool 45 is readily observed by reference to transparent sight tube 15. There is no overflow of oil from transparent sight tube 15 as a result of a higher unbalanced pressure within the housing 40. ln any regard, any overflow for whatever reason, e.g., as for adjustment or as a result of accumulation, is readily collected within container 23. The pressure within the latter container 23 is also maintained at the same level as in housing 40, and transparent sight tube 15, all of which are interconnected.

. There is never any reason for discharge of oil mist to the atmosphere, nor spillage as conventionally occurs in prior art devices.

Referring to FIG. 2 there is shown an even more we ferred oil mist lubrication and oil immersion system pursuant to this invention. It differs from the embodiment described by reference to the preceding figure basically in that the design of the oil mist inlet to the housing is further simplified, to provide more trouble-free operation, and the lower T connection 18 is combined as a part of the transparent sight tube which permits better visibility of the oil level, which is quite desirable when the oil level is low. A transparent sight collector, or drain "glass" is also optionally provided below the housing.

This structure, like the former, also includes a housing 80, within the enclosing wall 81 of which is journalled a shaft 82 set on bearings 84, partially immersed in a pool of oil 85. A loop communication 50 connects the upper and lower portions of the housing 80, this loop comprising the horizontal line 54 which is communicated with the upper portion of the housing via elbow, T and nipple connections 51,52,53, respectively, and with the lower portion of the housing 80 via elbow, transparent sight tube, union adapter and conduit 55,56,57,58, respectively. In this embodiment, oil mist at above atmospheric pressure is supplied via a line or conduit 48 communicated to the branched portion of T connection 52, the oil mist entering the housing 80 via the nipple 53, and loop 50 via line 54. The oil level is readily observed, even when relatively low, by reference to the transparent sight tube 56 which serves both as a transparent sight tube and T connection. An optional transparent sight tube 49, for observing the condition of the oil within the housing, is also located at the bottom of housing 80, being connected thereto via fittings 46,47.

An overflow collector 63 is similar to that described by reference to FIG. 1. The overflow collector 63 is thus communicated with and sealed within the lower portion of the transparent sight tube 56 via a relatively small diameter overflow tube 62. The tube 62 is affixed within the sight tube 56 via appropriate connections 59,60, and within the collector 63 via appropriate connections 64,65. A drain 66 is also provided on the bottom of collector 63, and optionally a bleed port 67.

The bleed port 67, where incorporated within the collector 63, is sized sufficiently small to maintain above atmospheric pressure within the collector 63,

and which pressure is necessarily substantially equal to that maintained within the housing 80 and loop 50. Suitably, when employing a pressure ranging from about to 7 inches of water, which is typical for an oil mist lubrication system, the diameter of the bleed port 67 ranges from about 1/32 to about 3/32 inch average diameter, and typically about l/l6 inch average diameter. Because of the problems of pollution, such bleed port 67 is only employed where there is insufficient labor to draw off the collected oil at adequate intervals.

It is apparent that various modifications and changes can be made without departing the spirit and scope of the present invention. The materials of construction are conventional, and substantially nonreactive to the chemical action of the oils contained within the system. Desirably, the tubular portions of the system, where transparency is desired, can be constructed of quartz, or the like, but generally and preferably are constructed ofa transparent plastic or plastic-like material. Since the oil level within the tubular portion, however, need not necessarily be visible for adjustment, they can also be constructed of an opaque material, e.g., metal. The use of metal may be particularly desirable for high temperature applications. Other portions of the system are normally constructed of metal.

It is also apparent that various changes, such as in the absolute or relative dimensions of the parts, materials used, and the like, can be made without departing the spirit and scope of the invention.

Having described the invention, what is claimed is:

1. Apparatus for use with an oil mist lubrication sys tern for the lubrication of machine elements and the like wherein an oil aerosol at above atmospheric pressure is conveyed via an aerosol supply conduit from said oil mist lubrication system, the combination which comprises:

a sealed housing, formed by an enclosing wall, within the confines of which there is mounted an end of a rotatable shaft which carries machine elements that are to be lubricated, a reservoir within the bottom of which an oil pool can be maintained at level sufficient that the lower portions of the machine elements can be partially immersed therein, and within which sealed housing an aerosol supply conduit is connected and in communication therewith for supply of oil aerosol at above atmospheric pressure to the housing,

a sealed closed loop conduit, one terminal end of which is connected to and in communication with the lower portion of the sealed housing below said oil level for supply of oil thereto, an intermediate portion at sufficient height above the bottom of the housing to permit an oil level to be maintained therein, and the opposite terminal end of which is connected to and in communication with an upper portion of the housing above the oil level,

oil collection means in open communication with, and in sealed relationship with said closed loop conduit,

whereby, oil aerosol supplied under above atmospheric pressure can enter into the upper portion of the closed sealed housing and into the vapor space of the housing via the aerosol supply conduit and into the upper portion of the closed loop conduit, and oil is provided ingress and egress to and from the oil pool at the bottom of the housing, lower portion of the closed loop conduit and intermediate portion of said closed loop such that an above atmospheric equilibrium pressure can be maintained upon the oil level in both the housing, closed loop circuit and oil collection means, this preventing fluctuating oil levels and differential pressures between the said housing and closed loop circuit.

2. The apparatus of claim 1 wherein the closed loop circuit contains a transparent sight tube at the intermediate location, the oil level being maintained therein to permit visual observation of the oil level within the housing.

3. Apparatus for use with an oil mist lubrication sys tem for the lubrication of machine elements and the like wherein an oil aerosol under pressure is conveyed via an aerosol supply conduit from said oil mist lubrication system, the combination which comprises:

a sealed housing, formed by an enclosing wall, within the confines of which there is mounted an end of a rotatable shaft carrying machine elements which are to be lubricated, a reservoir within the bottom of which can be maintained an oil pool at level sufticient that the lower portions of the machine elements can be partially immersed therein,

a first T-shaped conduit connection, an end of the axially aligned open portion of which is connected to a fitting and projected within the wall of the housing and through which conduit connection and fitting an aerosol supply conduit is projected to provide conduit means through which oil aerosol can be injected into the sealed housing, the upper end of the said T connection between the external wall of the aerosol supply conduit and inside wall of the said T connection being sealed to leave an annular passageway between the external wall of the aerosol supply conduit and branch opening within the said T connection,

a sealed closed loop conduit, an upper horizontal portion of which is connected with the side branch portion of the said T connection and in communication with the annular passageway therethrough, a vertically oriented portion, an end of which is in communication with said horizontal portion and the other of which is adjoined to an oil level control tube located at the same height as the surface level of the pool of oil maintained within the closed housing, the sealed loop circuit including a second T connection connected via its axially aligned open end with a conduit fitted to the oil level control tube, and a second horizontally oriented conduit portion below the said tube, an end of which is connected with the branch portion of said second T connection and the opposite end of which is communicated with the reservoir portion ofthe housing below the oil level, and

an oil collection means in open communication with, and in sealed relationship with said sealed closed loop circuit, which includes a tubular member, the bottom of which is closed by a container mounted thereon, the upper end of the tubular member being projected upwardly into the axial lower open end of the second T connection, and into the oil level control tube, the lower end of the axial portion of the T connection is sealed between the inside wall of the T connection and external wall of the said straight tubular member such that oil can overflow from the oil level control tube through the opening within the straight tubular member, and into the container mounted thereon,

whereby oil aerosol can enter via the aerosol supply conduit into the vapor space of the closed housing and via the annular passageway within the first T connection into the upper portion and transparent sight tube within the upper portion of the closed loop circuit, and oil from the reservoir of the housing is accorded ingress and egress into the lower portion of the closed loop circuit such that an equilibrium pressure is maintained upon the oil level in both the housing and closed loop circuit, this preventing fluctuating oil levels and differential pres sures between the said housing and said sealed closed loop circuit.

4. The apparatus of claim 3 wherein the oil level control tube contained within the closed loop conduit is transparent, and constitutes a sight tube for viewing the oil level.

5. The apparatus of claim 4 wherein the transparent sight tube is constructed of plastic.

6. The apparatus of claim 3 wherein the oil level control tube and second T connection are replaced by a single transparent T connection by virtue of which the oil level therein can be viewed and controlled.

7. The apparatus of claim 3 wherein the container mounted on the bottom of the tubular member constituting a portion of the oil collection means is transparent, and provided with a drain which can be opened at will to release oil overflowed from the oil level control tube.

8. The apparatus of claim 7 wherein a permanently open bleed port is contained within a wall of the container. and sized to maintain above atmospheric pressure as well as equalize the pressure within the housing, closed loop conduit and container.

9. The apparatus of claim 8 wherein the diameter of the bleed port ranges between about 1/32 and 3/32 inch, for pressures ranging about 5 to 7 inches of water.

10. The apparatus of claim 3 wherein a sight tube is located on the housing, below the oil level, for viewing the condition of the oil contained within the housing. i l l 

1. Apparatus for use with an oil mist lubrication system for the lubrication of machine elements and the like wherein an oil aerosol at above atmospheric pressure is conveyed via an aerosol supply conduit from said oil mist lubrication system, the combination which comprises: a sealed housing, formed by an enclosing wall, within the confines of which there is mounted an end of a rotatable shaft which carries machine elements that are to be lubricated, a reservoir within the bottom of which an oil pool can be maintained at level sufficient that the lower portions of the machine elements can be partially immersed therein, and within which sealed housing an aerosol supply conduit is connected and in communication therewith for supply of oil aerosol at above atmospheric pressure to the housing, a sealed closed loop conduit, one terminal end of which is connected to and in communication with the lower portion of the sealed housing below said oil level for supply of oil thereto, an intermediate portion at sufficient height above the bottom of the housing to permit an oil level to be maintained therein, and the opposite terminal end of which is connected to and in communication with an upper portion of the housing above the oil level, oil collection means in open communication with, and in sealed relationship with said closed loop conduit, whereby, oil aerosol supplied under above atmospheric pressure can enter into the upper portion of the closed sealed housing and into the vapor space of the housing via the aerosol supply conduit and into the upper portion of the closed loop conduit, and oil is provided ingress and egress to and from the oil pool at the bottom of the housing, lower portion of the closed loop conduit and intermediate portion of said closed loop such that an above atmospheric equilibrium pressure can be maintained upon the oil level in both the housing, closed loop circuit and oil collection means, this preventing fluctuating oil levels and differential pressures between the said housing and closed loop circuit.
 2. The apparatus of claim 1 wherein the closed loop circuit contains a transparent sight tube at the intermediate location, the oil level being maintained therein to permit visual observation of the oil level within the housing.
 3. Apparatus for use with an oil mist lubrication system for the lubrication of machine elements and the like wherein an oil aerosol under pressure is conveyed via an aerosol supply conduit from said oil mist lubrication system, the combination which comprises: a sealed housing, formed by an enclosing wall, within the confines of which there is mounted an end of a rotatable shaft carrying machine elements which are to be lubricated, a reservoir within the bottom of which can be maintained an oil pool at level sufficient that the lower portions of the machine elements can be partially immersed therein, a first T-shaped conduit connection, an end of the axially aligned open portion of which is connected To a fitting and projected within the wall of the housing and through which conduit connection and fitting an aerosol supply conduit is projected to provide conduit means through which oil aerosol can be injected into the sealed housing, the upper end of the said T connection between the external wall of the aerosol supply conduit and inside wall of the said T connection being sealed to leave an annular passageway between the external wall of the aerosol supply conduit and branch opening within the said T connection, a sealed closed loop conduit, an upper horizontal portion of which is connected with the side branch portion of the said T connection and in communication with the annular passageway therethrough, a vertically oriented portion, an end of which is in communication with said horizontal portion and the other of which is adjoined to an oil level control tube located at the same height as the surface level of the pool of oil maintained within the closed housing, the sealed loop circuit including a second T connection connected via its axially aligned open end with a conduit fitted to the oil level control tube, and a second horizontally oriented conduit portion below the said tube, an end of which is connected with the branch portion of said second T connection and the opposite end of which is communicated with the reservoir portion of the housing below the oil level, and an oil collection means in open communication with, and in sealed relationship with said sealed closed loop circuit, which includes a tubular member, the bottom of which is closed by a container mounted thereon, the upper end of the tubular member being projected upwardly into the axial lower open end of the second T connection, and into the oil level control tube, the lower end of the axial portion of the T connection is sealed between the inside wall of the T connection and external wall of the said straight tubular member such that oil can overflow from the oil level control tube through the opening within the straight tubular member, and into the container mounted thereon, whereby oil aerosol can enter via the aerosol supply conduit into the vapor space of the closed housing and via the annular passageway within the first T connection into the upper portion and transparent sight tube within the upper portion of the closed loop circuit, and oil from the reservoir of the housing is accorded ingress and egress into the lower portion of the closed loop circuit such that an equilibrium pressure is maintained upon the oil level in both the housing and closed loop circuit, this preventing fluctuating oil levels and differential pressures between the said housing and said sealed closed loop circuit.
 4. The apparatus of claim 3 wherein the oil level control tube contained within the closed loop conduit is transparent, and constitutes a sight tube for viewing the oil level.
 5. The apparatus of claim 4 wherein the transparent sight tube is constructed of plastic.
 6. The apparatus of claim 3 wherein the oil level control tube and second T connection are replaced by a single transparent T connection by virtue of which the oil level therein can be viewed and controlled.
 7. The apparatus of claim 3 wherein the container mounted on the bottom of the tubular member constituting a portion of the oil collection means is transparent, and provided with a drain which can be opened at will to release oil overflowed from the oil level control tube.
 8. The apparatus of claim 7 wherein a permanently open bleed port is contained within a wall of the container, and sized to maintain above atmospheric pressure as well as equalize the pressure within the housing, closed loop conduit and container.
 9. The apparatus of claim 8 wherein the diameter of the bleed port ranges between about 1/32 and 3/32 inch, for pressures ranging about 5 to 7 inches of water.
 10. The apparatus of claim 3 wherein a sight tube is located on the housing, below the oil level, for viewing the condition of the oil contained within the housing. 